Broncos not sure when Wolfe will return

ENGLEWOOD, Colo. -- The Denver Broncos still don't have a timetable for defensive end Derek Wolfe's return to the lineup.

Wolfe has been held out of practices this week, including Thursday's. He suffered what the team has termed "seizure-like symptoms" on the team's bus ride to Denver International Airport last Friday and spent the weekend in a Denver hospital.

Following Thursday's practice, Broncos head coach John Fox said doctors were still conducting tests to try to find the origin of Wolfe's issues.

"Still got a couple of things left to look [at]," Fox said. "Hopefully get him schooled up as far as not letting him get in that position again."

Asked if he could say yet whether Wolfe would return this season or be placed on injured reserve, Fox said he couldn't.

"We're probably where we were early in the week other than probably eliminating some things, some serious things, but we're still sorting it out ... We'll do what the medical people prescribe. He's not ruled out yet, but we don't know when he'll be back ... When that is I can't predict."

Kick returner Trindon Holliday (shoulder) was held out of practice for the second consecutive day. Tight end Joel Dreessen (left knee), who had been held out of Wednesday's practice, was a full participant Thursday.

Wide receiver Demaryius Thomas (left shoulder) was limited in the practice but is expected to play Sunday against the Tennessee Titans. Cornerback Dominique Rodgers-Cromartie (shoulder) and tight end Julius Thomas were both full participants and are on track to play against the Titans.

Quarterback Peyton Manning (right ankle) kept to his schedule of recent weeks and was back in practice after being held out Wednesday. Manning looked comfortable throwing the ball in temperatures that were hovering around three degrees at the start of practice.

The Broncos practiced outdoors in the frigid condition with Fox calling it "game-like conditions" and said Manning's day was "very good."

Linebacker Danny Trevathan (shoulder), defensive end Malik Jackson (knee), cornerback Champ Bailey (left foot) and running back Knowshon Moreno (right ankle) were all took part fully Thursday and expected to play Sunday.